#1
Whats up guys, seems like everytime I make a post on UG its about a problem I'm having. Anyways, I recently decided to buy as Peavy Classic 30 to replace my Fender Champ 20. I only had the amp for three weeks and I notice some issues with my Proco Rat 2 and the amo. When I engage the pedal and play, the volume sometimes shoots up, but then shoots right back down. Sometimes it does it back and forth like a tremolo. I should mention the fact that a long time ago I stupidly plugged a 12V adapter in this pedal, and it started to smoke. I knew at the time it was stupid I just didn't have a 9V adapter or battery at the time (again i know its stupid). So know inside the pedal, there is a small burn mark on one of the pedals inside components, so maybe it's the pedal?

When trying to troubleshoot the problem, I tried it with my old amp for nearly 10 minutes. But the problem disappeared. I bought new cables and the problem still remains. I tried it with a diff guitar same setup (c30 & rat pedal), the fluctuations came back. Tried putting it in the fx loop, same problem. The fact that the pedal is perfectly fine in the champ 20 leads me to believe its the c30s tubes or something. I bought this amp off ebay for $500 in mint condition though, maybe I was scammed? But one thing about this that makes me think its not the c30 is the fact that when the pedal is turned off there are absolutely no volume fluctuations. Most of my practice is with the pedal off, I only fiddle around with the pedal when Im done practicing.

I've never done anything to this amp. The only thing I did is that when I got it, I was moving the little black mat behind the speaker around, because I thought it was the channel foot switch ( I'm a tube amp noob, and still I don't even know what that mat is for). But again the problem goes away when the pedal is off. This is the only pedal I have btw so I cant try another pedal.

Update:

So it appears that the Champ 20 is also giving issues with the pedal. And my tube amp without the pedal is starting to fluctuate volume. Does this mean its tubes? I've tried checking the tubes by tapping the tubes with the amp off but im not hearing anything.

Here's a link of it happening with C30: https://www.youtube.com/watch?v=8qv9KqLyyiE

@ 0:09 you can hear the volume dip down, then at 0:25 goes back to normal, then straight back down. Usually, it stays at this volume and i feel like it should be the volume it went up to at 0:25.
Last edited by LikeWater at Sep 25, 2015,
#2
Sounds to me like you've blown something like a capacitor in the pedal.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#3
Quote by Cathbard
Sounds to me like you've blown something like a capacitor in the pedal.

but why does it only do it through the c30 and not the champ 20?
#4
Well, there is no coupling capacitor on the input of the Classic 30 so if the pedal is outputting DC it will unbias V1a. I can't find a schematic for the Champ 20, I'm guessing that it is decoupled.

Edit:. Oh sorry, the Classic 30 is decoupled. However, I'd still be repairing that pedal before proceeding. You know that it's broken - so fix it.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
Last edited by Cathbard at Sep 9, 2015,